Party-line signaling system.



H. M- BASCOM;

PARTY LINE' SIGNALING SYSTEM. APPLICATION man APR. 11. ms.

1,211,274., PatentedJan. 2,1917.

Q3 M I /n ven to r:

\ LQ/ Henry N. Bascpm,

nrirrnn snares Parana or tion.

HENRY M. BASCOIVI, or BROOKLYN, NEW Yoa'K, ASSIGNOR To .aME IcAn TELEPHONE AND TELEGRAPH COMPANY, a oonrona'rron o nEw roan.

PARTY-LINE SIGNALING SYSTEM,

Specification of Letters Patent.

Patented Jan; 2, 1917.

Application filed April 17, 1916. Serial No. 91,654.

To all whom it may concern:

Be it known that I, HENRY M. BAscoM, residing at Brooklymin the county of Kings and State of New York, have invented cer tain Improvements in Party-Line Signaling Systems, of which the following is a specification.

In the signaling organizations for multiparty telephone lines, commonly known as semi-selective machine ringing systems, it is customary when there are four substations connected with the line to transmit ringing currents selectively to the subscribers in groups of two over the two sides of the line, respectively, distinguishing between the stations joined to the same line conductor by distinctive code signals made up of alternate ringing and non-ringing intervals of diiferent duration. 7 An example of this in standard practice is where two substations receive ringing current over the tip and ring sides of the line, respectively, for two seconds followed by a silent interval of four seconds; while to the other two substations ringing current is similarly transmitted for one second with a succeeding silent interval of one second followed by a ringing'interval of one second and a silent interval of three seconds. These signals continue until the 'receiver is taken from the hook at one of the substations. They are produced by a source of signaling current connected to the line through one of two sets of segments of a continuously driven interrupter or controlling device, the particular set of segments utilized and the side of the line upon which ringing current is sent out being determined by one of a series of mechanically locking keys depressed by the operator. In herent in such arrangements is the possibility of an initial silent interval, after the operator has depressed the proper key and before the wiper which takes off current for the wanted substation is reached by the ringing segment so that ringing current becomes effective. In the particular example just given, this preliminary silent interval may vary from zero to eight'seconds. It is found'that when the called subscriber does not answer promptly, the continued frequent operation of the ringer annoys and becomes a cause of complaints from the'subscriber who is signaled over the same side of the line. Less trouble from this source would result were the silent intervals longer, but

if the interrupters are changed for this purpose there is the consequent lengthened initial' .period of delay with the attendant slowing down of the service. By my invention I am enabled to increase the silent grammatically a single embodiment of the invention applied to a. trunk-of which only one extremity is shown, this generally excluding parts not directly bearing upon this invention.

There is illustrated a cord circuit C of a B operator situatedat the incoming end of a trunk L, this including the 24-volt common battery B between the windings 0f the usual repeating coil Iand terminating inthe calling plug P for insertion in the jack J of a called line, as L; Individual to the cord is an interrupting or controlling mechanism D, here shown as consisting of a shaft cl having fixed to it disks d d2, 6Z3, andL d, which may be connected to the talking strands of the cord circuit, d and 0Z to the ring strand'and (Z d to the tip strand through mechanically locking'keys K K K and K respectively. These keys remain in their depressed position until released by the actuation of one of the other keys. The disks are arranged as usual,,with insulated segments 10 connected to the ringing generator G through the windingof a marginal relayR, and adjacent segments'll joined to the battery B or other source of continu ous'current by way of one winding of a relay R The shaft is rotated at the desired speed, which may be three and onethird revolutions per minute, by motor mechanism M including a friction disk m source of power and a cooperating disk m fast upon the shaft 'cZ and which may be drawn into driving engagement with the disk m by a magnet m Associated with the interrupter mechanism is controlling mechanism E, which may be-in the form of an additional interrupter disk (i securedv to the shaft (Z and having a long segment 12 provided with a battery connection and a short insulation segment 13. wiper 00-.

operating with the periphery of this disk (Z serves to unite its segments with the motor magnet m and also to the front armature of a relay B In addition to relays R, R and R al ready mentioned, the cord circuit is provided with relays R R R and R. Relay B, when energized by current over the trunk, causes the illumination of the guard and disconnect lamp 0 and makes the first closure of a circuit for energizing relays R and R Relay R has its winding in the sleeve strand of the cord C. It closes at its front contacts a break in one of the talking strands of the cord, completes the circuit of relays R and R and prepares for the extinguishment of the lamp 0. l Vhen relay R attracts its armature it opens the talking strands of the cord, joining the outgoing ends to the ringing keys. Relay R controls the energization of the motor magnet m to start the rotation of the interrupter mechanism D. The removal of the receiver from its hook at the substation of line L operates either relay R or R depending on whether it is during the ringing or silent interval. Relay R controls the release of relays and R By relay R the customary supervisory functions are exercised.

In detail the oaeration of the rin in system is as follows: An A operator having connected one of her cord circuits with the trunk L, the relay R receives current through its winding let over the trunk conductors and through windings 15 of the repeating coil I from battery in the A operators cord. Contact 16 of relay R is thereby closed givinga circuit to the lamp 0 by way of resistance r, resting contact 17 of relay R conductor 18, contact 16 and conductor 19. As this lamp acts in a wellknown manner, its operation will not be particularly described. The B operator, upon receiving the number of the called line, depresses the key, as K corresponding to the particular substation desired and places the plug P in the proper jack, as J. Upon cooperation of the plug and jack re-- lay R is energized over sleeve conductor 20 and the corresponding contacts of the jack and plug. Contacts'21 of relay R closes a break in the tip strand 22 of the cord C. It also breaks contact 17 and closes contact 23. There is now a circuit including the sleeve contacts of the jack J and plug P, strand 20, winding of relay R conductor 19, contact 16 of relay R conductor 18, Contact 23 of relay R conductor 24:, back contacts 25 and 26 of relays R and R respectively, and the windings of relays R and R This circuit shunts the lamp 0 and eXtinguishes it. Relay R is maintained operated and relays R and R are energized. At the back contacts 27 and 28 relay Pf severs the talking strands 22 and 29 and at front contacts 31 and 30 joins the tip and ring of the plug P to the springs, and consequently to the make contacts, of key K. The front contact 32 of relay R gives a path for current to magnet m The disk m is attracted against the driven disk m and thus imparts rotary movement to the shaft 03 in the direction of the arrow. The make contact 33 of key K now closed, is united by a conductor 34 to the wiper which normally rests upon the segment 11 of disk al just clear of the seg ment 10, which is brought under the wiper by rotation of shaft (Z. 'Consequently ringing current at once flows from the generator G through the winding of relay R (which does not operate for this strength of current) conductor 35, segment 10 of disk (Z and the cooperating wiper, conductor 34-, contact 33 of key K on through the make contacts of keys K K and K in series, contact 30 of relay R ring strand of the cord and contacts of the plug and jack, over the ring side of the line and through the ringers of the two substations connected thereto to ground. For the disk (Z the segment 10 is shown as having one eighth the peripheral extent of the segment 11. At the rate of rotation previously stated this will operate the ringers of the two substations for two seconds, followed by a sixteen second interval of silence when the wipers are in contact with segment 11. When the subscriber at the substation to which this particular signal has been assigned removes the receiver from its hook the resulting increased flow of current causes relay R to attract its armature, if ringing current is at this time passing. The opening of contact :25 breaks a short circuit of the winding 36 of relay R and said relay is energized by the passage of current through this winding, the path be ing the same as that described in connection with the energization of relays R and R except that the conductor 38 and the winding 36 are now substituted for the portion including contacts 25 and 26. During the silent interval winding 39 receives batterycurrent over the line, this flowing from conductor 34 by way of the segment 11 and conductor 40, energizing relay R The short circuit of winding 36 is thus opened at contact 26. As the cessation of signaling is initiated by different relays during the ringing and silent intervals, that responsive to battery current may be designed without reference to the requirements of a relay operated by alternating current. Therefore the usual common battery of 24 volts may be employed to operate relay R During either interval, upon the removal of the short circuit, relay R locks itself through contact 41, and in sodoing short circuits relays R and R which are thus released. The last-named relay severs the ringing circuit at contacts 30 and 31 and completes the continuity of the talking'strands at contacts 27 and 28. Relay R is now under the influence of the substation switch hook and with the relay R controls the calling supervisory lamp at the A operators position 'in a manner well-known. The initiating cir-' cuit of the motor magnet m is opened at contact 3270f relay R If the insulating segment 13 of disk is beneath the cooperating wiper the motor magnet is deprived of current, releasing the 'disk m from the driving disk m and the rotation of the interrupter ceases. If the de'ner'gization of relay R occurs while the battery segment 12 of the disk (Z is beneath'the wiper, the rotation continues 'by virtue of this circuit connection for the motormagnet until the segment 13 reaches the wiper,

when the interrupter is stopped in as normal position. 7 It will therefore be seen that regardless of the length of the silent inter.

val, ringing will begin promptly upon the insertion of the plug in the jackfof the called line and the depression of the key K the desired initial silent interval being determined by the device 0Z Were the key K the one actuated the effect would be the same, except that in the corresponding disk (Z there are two of both the ringing and silent segments so arranged as to provide for operation of the substation ringers connected to the ring side ofthe line for one second immediately after the depression of the key, with succeeding intervals of one second of silence, one second of signaling and fifteen seconds of silence, after which the cycle is repeated as in the first instance until the subscriber answers.

Disks (Z and cl" corresponding to keys K and K resemble, respectively, (Z (Z in their effects, but the relation of their wipers to the segments is such that ringing does not begin until the interrupter has been in vrotation for two seconds. This gives a nonringing period for the tip of the plug to pass the ring contact of the jackduring the insertion of the-former, thus avoiding the passage of signaling current over the wrong side of the line. 7

At the close of the conversation, relay, R having been deenergized by the opening of the line L as a consequence of the return of the substation receiver to its hook, the removal of the plug of the A operators cord from the jack at the outgoing end of the trunk L releases relay R and opens at contact 16 the locking circuit of relay R which releases. The releasing of relay R also opens the shunt around the lamp 0, causing it to" light. Thereupon the B operator removes the plug P from the jack I J, thus releasingrelay R The apparatus of the cord circuit C is now in normal posltion except the rlngmg keys. As to these,

the last one depressed may be left locked down, to be released if another in the series is actuated upon the next connection or a peated. Similarlv. if the B operator takes" out and replaces the plug under her control, the opening and closing of the sleeve circuit at the contact of the jack and at contact 23 of relay R will cause the ringing operation to be repeated.

I claim:

1. In a signaling system for producing signals at predetermined intervals, a source of signaling current and, conductors to wh ch said current 1s to be applied, mechanism between the current'sources and conductors for applying said current in successive cycles of predetermined intervals, a device operableto render the controlling mech anism effective, and means for determining the interval after whichthe source and conductors shall be connected following the operation of the device.

2; In a signalingisystem for producing signals at predeterminedintervals, a source of signaling current and conductors to which said current is to be applied, normally stationary mechanism between the current source and conductors adapted when set in operation to apply said current in successive cycles of predeterminedintervals, a device operable to start the controlling mechanism and means to determine the position from which the controlling mechanism starts.

3. The combination with substation lines, of a connecting circuit therefor, a source of signaling current, an interrupting mechanism between the connecting circuit and current source, motor mechanism for the interrupting mechanism, means for starting the motor mechanism when the connecting circuit is joined to the substation lines, and means controlled by a substation for rendering the motor mechanism ineffective. V

4. The combination with telephone lines,

of a connecting circuit therefor, a source of a signaling current, an interrupting mechanism between the connecting circuit and curstopping the motor mechanism upon the response of the called subscriber.

5. In a machine ringing system, lines to be signaled and switching means therefor, a source of ringingcurrent, an interrupter, motor mechanism therefor, and a relay controlling the motor mechanism and controlled by the switching means.

6. In a machine ringing system, lines to be signaled and switching means therefor, a source of ringing current, an interrupter, motor mechanism therefor, and a relay controlling the motor mechanism and controlled by the called line. i

7. In a machine ringing system, lines to be signaled and switching means therefor, a source of ringing current, an interrupter, motor mechanism therefor, and relays controlling the motor mechanism and controlled by the called line and by the switching means.

8. In a machine ringing system, lines to be signaled and switching means therefor, a source of ringing current, an interrupter, motor mechanism therefor, relays controlling the motor mechanism and controlled by the called line and by the switching means, and means movable with the interrupter for also controlling said motor mechanism.

9. In a machine ringing system, lines to be signaled and switching means therefor, sources of ringing current and continuous current, an interrupter, motor mechanism therefor, relays for controlling the motor mechanism, and circuits for the relays controlled by the called line and including respectively the ringing current source and the continuous current source.

10. The combination with telephone lines and a connecting circuit therefor, of sources of ringing current and of continuous current, relays in the connecting circuit for controlling the application of ringing current to the called line, and circuits for said relays one of which is operated by ringing current in one of said circuits.

'11. In a machine ringing system, lines to be signaled and switching means therefor, sources of ringing current and continuous current, an interrupter for said currents, motor mechanism for the interrupter, relays for controlling the motor mechanism, one of said relays being controlled by another, and circuits for the relays controlled by the called line and including respectively the ringing current source and the continuous current source.

12. Ina machine ringing system, lines to be signaled and switching 'means therefor,

sources of ringing current and continuous current, an interrupter for said currents, m0- tor mechanism for the interrupter, relays for controlling the motor mechanism, one of said relays being controlled by another, energizing circuits for the relays controlled by the called line and including respectively the ringing current source and the continuous current source, and a locking circuit for that relay which is under the control of the associated relay.

In testimony whereof I have signed my name to this specification, this 13th day of April, 1916.

HENRY M. BASCOM.

Copies ,of this patent may be obtained for five cents each, by addressing the Commissioner of Eatents,

Washington, D. G. 

